A gas turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. Air entering the compressor section is compressed and delivered into the combustion section where it is mixed with fuel and ignited to generate a high-energy exhaust gas flow. The high-energy exhaust gas flow expands through the turbine section to drive the compressor and the fan section. The compressor section typically includes a first (low) pressure compressor and a second (high) pressure compressor, and the turbine section includes low and high-pressure turbines.
A speed reduction device such as an epicyclical gear assembly may be utilized to drive the fan section such that the fan section may rotate at a speed different than the turbine section so as to increase the overall propulsive efficiency of the engine. In such engine architectures, a shaft driven by one of the turbine sections provides an input to the epicyclical gear assembly that drives the fan section at a reduced speed such that both the turbine section and the fan section can rotate at closer to optimal speeds.
Lubrication of the speed reduction device is provided to maintain thermal and power transfer efficiencies. During normal operations a primary lubrication system supplies lubricant at a desired flow rate and pressure. An auxiliary lubrication system may also be included to provide lubrication during periods in which the primary lubrication system may not provide sufficient lubrication such as during extreme aircraft maneuvers. Pressure sensors within the lubrication system monitor lubricant pressures and detect any fault conditions. Pressure within the auxiliary lubricant circuit is pressurized by the primary system during normal operations and therefore detecting pressures to monitor the health of the auxiliary system provides only limited accuracy.
Accordingly, engine manufacturers continually seek improvements in operational efficiency and monitoring to maintain engine functionality.